Congregants, wearing caps and flannels and tagged with tattoos, bounced in their sneakers in preparation for the day’s sermon.

Instead of Methodists filling the sanctuary of the 1839 house of worship, the visitors are youths with trouble in their not-too-distant past. “I was locked up for a while and that was my community,” said Jesse Battista, 20, of Lowell, addressing the morning gathering called Fresh Inspirations at the United Teen Equality Center.

Now in its 13th year, the nonprofit that gives gang-afflicted, crime-ridden, and disenfranchised Lowell 16- to 24-year-olds a second chance finally has a space befitting its mission. Using the latest in green technology, the once nomadic drop-in center has turned a crumbling church into an icon of sustainability and secured its future.

“We are not just building a green building and leaving it at that. It’s a model for high-performance energy efficiency,” said Gregg Croteau, UTEC’s executive director, on a recent tour of its sleek new atrium awash in natural light.

UTEC’s $8.5 million green urban youth center officially opens this month. With funding from the city of Lowell, federal stimulus aid, and several well-known charitable foundations and individuals, the repurposed space is “a harbinger of things to come,” said Susan Kaplan, director of marketing for the Massachusetts Department of Energy Resources.

The state agency allocated $1.9 million from the American Recovery and Reinvestment Act to help UTEC retrofit the church into a sprawling space for teens to dance, learn algebra, debate politics, and become environmentally aware.

The building’s highlights — such as soy insulation, a passive cooling system, and electric car-charging stations — mean the teen center is “becoming sophisticated,” said Phil Hall, an administrator at the Theodore Edson Parker Foundation, which gave UTEC a $300,000 grant for the project. “UTEC really is that model of urban youth programming. It stands out as a model of excellence.”

Wendy Maeda/Globe Staff

Jesse Leverone, left, attended a debate club meeting in a new classroom at UTEC in Lowell.

What was once a packed chapel is now a performance and conference space for dance jams and movies, and big enough to host a Ted Talk. On top of the church is a network of solar panels, which will cut energy bills considerably.

Perhaps the most visible change is the cafe, which will open next year to the public. In an angular space furnished with repurposed wood from the church’s original floor, the youth-run restaurant will serve farm-to-table meals and homemade bread from UTEC’s Fresh Roots
culinary arts program.

To add clout to its efforts, UTEC has applied for LEED (which stands for Leadership in Environmental and Energy Design) platinum certification from the US Green Building Council. If approved, the center will be the oldest building in the country with that distinction. In this business of confidence-building, such accolades make a difference.

“The environment dictates the behavior of our young people,” said Croteau, adding that UTEC members had a green building on their wish-list from day one. “Young people have always been in the lead. They create movement.”

And lately, there’s been major movement at 34 Hurd St.

Thanks to an 8,000-square-foot addition, UTEC will double enrollment in its alternative high school/job training programs while reducing energy consumption by 68 percent. But, akin to Rocky’s rise to the top, this is a story about the will to survive.

Wendy Maeda/Globe Staff

Executive director Gregg Croteau addressed the morning gathering.

In a city with 25 active gangs, according to the Lowell Police Department, UTEC has had a constant demand for its services.

The organizations started out as a group of reformed gang members roaming the city’s most violent neighborhoods to keep the peace.

But street workers soon realized they could not break through without “a safe haven, a neutral zone,” said Croteau.

Bouncing around church halls and vacant rooms above storefronts since 1999, the nonprofit purchased the church in 2006. Dingy with pigeon dung, a leaky roof, and cracked windows, the building was so outmoded, it cost the parish $5,000 a month to heat the space with an old boiler, said Croteau. UTEC moved in the following year and began raising funds to improve the historic structure with efficient and green updates.

Just as the neon pumpkin-jacket-wearing street workers chip away in the city’s rough back alleys mending broken lives, UTEC’s members have been scraping, painting, building railings, and hammering away with a carpenters’ union to create their new home. The project employed 30 youths in the process.

“Whatever they do, they try to do it ambitiously. UTEC always goes the other way trying to be progressive and shoot high,” said Hall, who equates UTEC’s green facility with standout urban youth centers like Roca in Chelsea and Artists for Humanity in South Boston.

In the highest part of the church, the steeple is now a natural flue that circulates hot air out of the building in the summer, with the help of a giant fan centered in an ornate medallion above the former pulpit.

Wendy Maeda/Globe Staff

Street workers Jonathan Lunde and Louie Diaz paint an office in the United Teen Equality Center’s new home.

“The project teaches the next generation about sustainability, how to reduce energy use, and protect the environment,” said Krista Selmi, assistant secretary for public affairs for the state’s Executive Office of Energy and Environmental Affairs.

“We hope it can serve as an example for other communities in the Commonwealth,” she said.”

UTEC has long been an example for high school dropouts, young mothers, and wayward teens. In small classes they work on getting high school diplomas and GEDs.

A team of transitional coaches helps members navigate the complicated social services maze and a workforce program employs them in food service, mattress recycling, and building maintenance. In a city like Lowell, this has an outsized impact.

“They help youths stay involved in their own future and get them new jobs. UTEC has provided these young people with a choice,” said Lowell City Manager Bernie Lynch.

So impressed was Lynch with UTEC when he became city manager in 2006, that the city of Lowell has invested more than $1 million to see it flourish. “The streets are safer with the work they are doing and the lives of so many young people they’ve touched,” Lynch said.

And now they are giving back.

The car-charging station is free to residents until next year and a large performance space and several meeting rooms with pleasing views of the downtown are available for community events. Fresh Roots, overseen by a professional chef, is now catering functions.

When UTEC workforce development program supervisor Sako Long, a Cambodian immigrant who joined a gang at age 13, needs to connect with “the hardest of the hard” in the city, it helps to have a bright and clean building to bring them to.

“The space is a huge draw to keep students here,” said Long, who teaches ex-convicts communication skills to prepare them for the workforce.

Long is excited about the soon-to-come recording studio, where the next “American Idol” contestants may find their voice. The cafe’s pending pizza oven is another highly anticipated addition.

“The more we give back to the community, the more they will give back to us,” said Long, a beaming, well-spoken 33-year-old who spent four years in jail.

Beyond the green updates, UTEC’s core mission is stronger than ever. “It has more to do with the nature of the kids that they are serving and the way they treat these kids, as assets rather than problems,” Hall said.

Szifra Birke, a lifelong Lowell resident who donates her time and finances to UTEC, feels the same way. “I’m both worried about how things are for disenfranchised youth and excited about the opportunities available to help them.”

Birke felt compelled to help UTEC after her first visit years ago. “I was halfway through the tour and my heart melted four times,” she said. “I am so behind what this organization is about.”